India has about 2.5 million people infected with the AIDS virus, less than half of previous estimates, the Indian health minister and U.N. health officials said yesterday.

As a result, instead of having an estimated 5.7 million cases – the most in the world – India is in third place, behind South Africa, with 5.5 million, and Nigeria, with 2.9 million.

In the past, India was accused by many global AIDS officials of denying its epidemic and doing too little to prevent it.

Now skeptics who challenged the earlier numbers, including some Indian political figures and U.S. epidemiologists, have been vindicated.

However, the health minister, Dr. Anbumani Ramadoss, was quick to say that the threat to his country of 1.1 billion people was still serious. “In terms of human lives affected, the number is still large, in fact very large,” he told a news conference in New Delhi. “This is very worrying for us.”

The estimate was revised downward, according to the U.N. AIDS program, Unaids, because of a national survey that included blood samples of more than 100,000 people taken in 2005 and 2006. Called the National Family Health Survey III, it was paid for largely by the U.S. Agency for International Development.

Previous estimates had been based on blood samples taken from women visiting prenatal clinics, patients at sexually transmitted disease clinics and small samplings in high-risk groups such as prostitutes, truckers, intravenous drug users and gay men.

But the prevalence rates were distorted because there were few samples from men, rural dwellers, the middle class, and people outside industrialized southern India and the Myanmar border, where the disease is concentrated.

The new survey suggests that India's epidemic is more like that in the United States, concentrated in high-risk groups, rather than like the generalized epidemics in southern Africa.

While the new HIV estimates were a result of statistical breakthroughs more than medical ones, Ramadoss said that India's HIV-infection rate showed cause for optimism with a decline from about 0.38 percent of the adult population in 2002 to about 0.36 percent now.

According to 2005 U.N. figures, about 0.6 percent of the U.S. adult population is HIV-positive.

Also yesterday, the Indian health minister announced a new phase of the federal AIDS control program, with the government pledging $1.95 billion – nearly 40 times what it spent in the last round.

This new plan has an expected budget of $2.8 billion and has attracted high-profile donors, including the Bill & Melinda Gates Foundation, the Clinton Foundation and the U.N. Development Program.

The previous plan, announced in 1999, had a budget of less than $350 million.

The new plan will include condom promotion, education, and treatment and care of those with HIV.

In the next two years, India wants to open 250 AIDS treatment centers and hopes to test 42 million people by 2012.

The Associated Press, The Washington Post and Reuters contributed to this report.